KR20070075303A - Ph buffered aqueous cleaning composition and method for removing photoresist residue - Google Patents

Abstract

A cleaning composition is provided to have high selectivity to residues and remove photoresist residues and process residues from a substrate. The cleaning composition for removing residues from a substrate comprises (a) water, (b) at least one fluoride, and (c) a pH buffer system including (i) at least one organic acid selected from the group consisting of aminoalkyl sulfonic acid and aminoalkyl carboxylic acid and (ii) at least one base selected from the group consisting of amine and quaternary alkylammonium hydroxide. The composition is substantially free of organic solvent to be added and has a pH of about 5-12.

Description

pH buffered aqueous cleaning composition and method for removing photoresist residues {pH BUFFERED AQUEOUS CLEANING COMPOSITION AND METHOD FOR REMOVING PHOTORESIST RESIDUE}

 The present invention generally relates to cleaning compositions and methods for removing photoresist residues from semiconductor device substrates after plasma etching and ashing processes in integrated circuit fabrication.

Many steps are involved in the fabrication of microelectronic structures. Within the production plan of integrated circuit fabrication, selective etching of different surfaces of semiconductors is often required. Historically, a large number of very different types of etching processes have been successfully used to varying degrees for selective removal of materials. Moreover, selective etching of different layers in the microelectronic structure is considered an important step in the integrated circuit fabrication process.

In the production of semiconductors and semiconductor microcircuits it is frequently necessary to coat substrate materials with polymeric organic materials. Examples of some substrate materials include aluminum, titanium, copper, silicon dioxide coated silicon wafers (optionally having metallic elements of aluminum, titanium, or copper), and the like. Typically, the polymeric organic material is a photoresist material. This is a material for forming an etch mask during development after exposure.

In a subsequent process step, at least some photoresist is removed from the substrate surface. One common method of removing photoresist from a substrate is by wet chemistry. Wet chemical compositions formulated to remove photoresist from a substrate do not damage the substrate (eg, corrode, dissolve, and / or dulling of any metallic circuit surface of the substrate; chemical modification of an inorganic substrate; and / Or attack of the substrate).

Another method of removing the photoresist is dry ashing, wherein the photoresist is removed by plasma ashing with a forming gas such as hydrogen or oxygen. The residue or byproduct can be the photoresist itself or a combination of photoresist, underlying substrate and / or etching gas. These residues or byproducts are often referred to as sidewall polymers, veils or fences.

Reactive ion etching (RIE) is increasingly being chosen as a process for pattern transfer during via, metal wire and trench formation. RIE processes typically leave residues or complex mixtures, which can be used to lithographically define re-sputtered oxide materials, organic materials from photoresists, and / or vias, metal lines and / or trench structures. And a reflective coating material.

The prior art teaches various cleaning compositions designed to remove residues and by-products resulting from semiconductor manufacturing processes. However, compositions that were once suitable for cleaning semiconductor materials of the day are not so suitable for use in more recently developed materials such as organosilica glass (OSG) dielectric materials and other low-k dielectric materials.

For example, U.S. Pat.Nos. 5,698,503 (Ward et al.), 5,792,274 (Tanabe et al.), 5,905,063 (Tanabe et al.), 5,962,385 (Maruyama et al.), 6,235,693 (Cheng et al.), 6,248,704 (Cheng et al.) Small et al.), 6,638,899 (Wakiya et al.), 6,677,286 (Rovito et al.), 6,773,873 (Seijo et al.), 6,821,352 (Rovito et al.) And 6,828,289 (Peters et al.) And US Patent Application Publication No. 2004 / 0016904 (Baum et al.) Discloses a cleaning composition comprising an organic solvent. Organic solvents may be unsuitable for use with some low-k dielectric materials when reacting with organic and hydrogen substituents to produce chemically modified dielectric materials.

US 6,197,733 discloses a cleaning composition comprising water, an ammonium fluoride compound, and an amphoteric surfactant wherein the cationic group is an ammonium salt and the anionic group is a carboxylate. This patent does not make any reference to the pH of the composition.

The pH of the cleaning composition is an important factor in the effectiveness of removal of residues and the like and compatibility with the substrate to be cleaned. In the presence of a strong acid or strongly basic aqueous composition, the Si-O and Si-H bonds of the low-k dielectrics can be converted to OH groups to increase the dielectric constant of the low-k dielectrics. Moreover, strongly acidic cleaning compositions containing hydrofluoric acid are not very suitable for use in aluminum, aluminum alloys containing copper, copper or carbon doped oxides. Therefore, the use of buffers in cleaning compositions has been proposed to maintain the pH within the desired range.

For example, US Patent Application Publication No. 2004/0266637 (Rovito et al.) Discloses an aqueous buffered fluoride containing composition having a pH of greater than 7.0 to about 11.0. The buffer composition is said to have an extended lifetime, since pH dependent properties such as oxide and metal etch rates are stable as long as the pH remains stable.

US Patent Application No. 11 / 050,562, assigned to Air Products and Chemicals, Inc., discloses cleaning compositions and methods of removing residues, wherein the compositions have a pH in the range of about 2 to about 9 Organic acids and conjugate bases of these organic acids in an acid to base molar ratio ranging from 10: 1 to 1:10; Fluoride and water, provided that the composition is substantially free of added organic solvent.

All documents cited herein are hereby incorporated by reference in their entirety.

Notwithstanding advances, it is therefore desirable to provide selective cleaning compositions and methods capable of removing residues such as residual photoresists and / or process residues such as, for example, residues resulting from selective etching and / or ashing. Required. Moreover, metal, high dielectric constant materials (referred to herein as "high-k" dielectric materials) which may remove residues such as photoresist and / or post-etching / ashing residues, which may also be exposed to the cleaning composition. ), High selectivity for residues relative to interlevel dielectric materials, including low dielectric constant materials (referred to herein as "low-k" dielectric materials), such as silicon, silicides, and / or deposited oxides. There is a need to provide optional cleaning compositions and methods. There is also a need to provide compositions that are compatible with and can be used for sensitive low-k thin films such as HSQ, MSQ, FOx, black diamond, and TEOS (tetraethylsilicate).

Summary of the Invention

Accordingly, a first aspect of the invention provides a composition for removing residue from a substrate, comprising: (a) water; (b) one or more fluorides; And (c) at least one organic acid selected from the group consisting of (i) aminoalkylsulfonic acids and aminoalkylcarboxylic acids; And (ii) a pH buffer system comprising at least one base selected from the group consisting of amines and quaternary alkylammonium hydroxides, wherein the composition is substantially free of added organic solvent and has a pH in the range of about 5 to about 12. to provide.

A second aspect of the present invention provides a method for removing residue from a substrate comprising contacting the residue with a composition of the present invention at a temperature and time effective to remove the residue from the substrate.

A third aspect of the invention provides a method of coating a photoresist on at least a portion of a substrate; Lithographically defining a pattern on the photoresist; Transferring the pattern onto at least a portion of the substrate; Etching the pattern onto a substrate to form a patterned substrate; Ashing the photoresist to provide a residue; And removing the residue by contacting the residue with a composition of the present invention.

Detailed description of the invention

Disclosed herein is a composition for selectively removing residue from a substrate and a method comprising the same. The compositions disclosed herein can selectively remove residues, such as process residues, from a substrate without attacking (to any desired degree) the structural material of the substrate, which may also be exposed to the cleansing.

As used herein, the term "residue" refers to the undesirable material present on the substrate. Residues that can be removed with the present invention include, but are not limited to: organic compounds, such as exposed and ashed photoresist materials; Ashed photoresist residue; UV or X-ray cured photoresists; C-F containing polymers; Low and high molecular weight polymers and other organic etching residues; Inorganic compounds such as metal oxides; Ceramic particles and other inorganic etch residues from chemical mechanical planarization (CMP) slurries; Metal containing compounds such as organometallic residues and metal organic compounds; Ionic and neutral, light and heavy inorganic (metal) species; moisture; And particles produced by processes such as planarization and etching processes. In one particular embodiment, the residues to be removed are process residues such as those produced by reactive ion etching and ashing.

The present invention is suitable for removing residues from various substrates. Suitable substrates include, but are not limited to: metal, silicon, silicate and / or interlevel dielectric materials such as deposited silicon oxide and derivatives such as HSQ, MSQ, FOx, TEOS and spin-on glass. Silicon oxide, and / or high-k materials such as hafnium silicate, hafnium oxide, barium strontium titanium (BST), Ta ₂ O 5, and TiO ₂ . Suitable substrate metals include, but are not limited to, copper, copper alloys, titanium, titanium nitride, tantalum, tantalum nitride, tungsten and titanium / tungsten.

Because of the specificity of the composition of the present invention, the present invention is not only intended to remove residues, but also the components of the substrate such as metals, silicon, silicides, interlevel dielectric materials, high-k materials and / or low-k materials. In particular). In addition, the compositions disclosed herein may exhibit the minimum etch rate of some dielectric materials, such as silicon oxide.

The compositions disclosed herein comprise a buffer solution comprising water, fluoride and organic acids and bases. In certain embodiments, the composition is substantially free of or contains no more than 2% by weight, or 1% by weight or less of organic solvent added. In certain embodiments, the composition is adjusted to a pH in the range of about 5 to about 12 and optionally includes corrosion inhibitors and other additives typically used in ashed photoresist and / or process residue removal compositions. In one specific embodiment, the composition comprises a buffer solution in an amount necessary to obtain a composition having a pH in the range of 5-12; At least 65% by weight of water; Fluoride 0.1 to 5% by weight; And up to 15% by weight of an optional corrosion inhibitor.

As mentioned above, the compositions disclosed herein comprise a buffer solution. As used herein, the term "buffer solution" is a solution that resists the pH change caused by addition of a small amount of acid or base to the composition. The buffer solution provides a buffer composition having a pH adjusted to minimize corrosion of sensitive metals such as, for example, tungsten, copper, titanium, and the like, when included in the compositions disclosed herein. Buffer solution is added in the amount necessary to obtain the desired pH range for the composition. The addition of the buffer solution to the compositions disclosed herein prevents pH fluctuations due to dilution with water or contamination with bases or acids.

The normal ratio (ie equivalent / molar ratio) of one or more organic acids to one or more bases is from 10: 1 to 1:10, or from 3: 1 to 1: 3, or substantially 1: 1. The ratio of the buffer solution is adjusted as necessary to obtain the desired pH range of the composition. Buffers are commonly considered weak acids and the broadest buffer range for an acid or base is about 1 pH units in either direction of the pK _a of the weak acid groups.

The buffer solution contains at least one organic acid selected from the group consisting of aminoalkylsulfonic acids and aminoalkylcarboxylic acids. The organic acid preferably has _a pK _a of about 6 to about 11. Aminoalkylsulfonic acid is represented by Formula 1:

Wherein R is an aminoalkyl group, including but not limited to primary, secondary and tertiary aminoalkyl groups, suitable alkyl groups of the aminoalkyl group R are straight chain alkyl, branched chain alkyl, cyclic alkyl, heterocyclic alkyl, Saturated alkyls, unsaturated alkyls, alkanes, alkyenes, alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, amides, and the like.

Non-limiting examples of suitable aminoalkylsulfonic acids are listed in Table 1 below.

Aminoalkylsulfonic acid Abbreviation Full name pKa MES 2- (N-morpholino) ethanesulfonic acid 6.1 ACES N- (2-acetamido) -2-aminoethanesulfonic acid 6.8 PIPES 1,4-piperazidaeethanesulfonic acid 6.8 MOPSO 3- (N-morpholino) -2-hydroxypropanesulfonic acid 6.9 BES N, N-bis (2-hydroxyethyl) -2-aminoethanesulfonic acid 7.1 MOPS 3- (N-morpholino) propanesulfonic acid 7.2 TES N-tris (hydroxyethyl) methyl-2-aminoethanesulfonic acid 7.4 HEPES N- (2-hydroxyethyl) piperazine-N '-(ethanesulfonic acid) 7.5 DIPSO 3- [N, N-bis (2-hydroxyethyl) amino] -2-hydroxypropanesulfonic acid 7.6 MOBS 4- (N-morpholino) butanesulfonic acid 7.6 TAPSO 3- [N-tris (hydroxymethyl) methylamino] -2-hydroxypropanesulfonic acid 7.6 HEPPSO N- (2-hydroxyethyl) piperazine-N '-(2-hydroxypropanesulfonic acid) 7.8 POPSO Piperazine-N, N'-bis (2-hydroxypropanesulfonic acid) 7.8 EPPS N- (2-hydroxyethyl) piperazine-N '-(3-propanesulfonic acid) 8 HEPBS N- (2-hydroxyethyl) piperazine-N '-(4-butanesulfonic acid) 8.3 TAPS N-tris (hydroxymethyl) methyl-3-aminopropanesulfonic acid 8.4 TABS N-tris (hydroxymethyl) methyl-4-aminobutanesulfonic acid 8.9 AMPSO 3-[(1,1-dimethyl-2-hydroxyethyl) amino] -2-hydroxypropanesulfonic acid 9 CHES 2- (N-cyclohexylamino) ethanesulfonic acid 9.3 CAPSO 3- (cyclohexylamino) -2-hydroxy-1-propanesulfonic acid 9.6 CAPS 3- (cyclohexylamino) -1-propanesulfonic acid 10.4 CABS 4- (cyclohexylamino) -1-butanesulfonic acid 10.7

Aminoalkylcarboxylic acids are represented by formula 2:

Wherein R is an aminoalkyl group, including but not limited to primary, secondary and tertiary aminoalkyl groups, suitable alkyl groups of the aminoalkyl group R are straight chain alkyl, branched chain alkyl, cyclic alkyl, heterocyclic alkyl, saturated Alkyl, unsaturated alkyls, alkanes, alkyenes, alcohols, ethers, sulfides, thiols, aldehydes, ketones, carboxylic acids, esters, amides and the like.

Non-limiting examples of suitable aminoalkylcarboxylic acids are listed in Table 2 below.

Aminoalkylcarboxylic acid name pK ₁ pK ₂ pK ₃ Glycine 2.35 9.78 β-alanine 3.55 10.24 L-serine 2.19 9.21 L-cysteine 1.5 8.7 L-asparagine 2.1 8.8 L-alanine 2.34 9.87 L-Glutamine 2.17 9.13 L-Isoleucine 2.32 9.76 L-leucine 2.33 9.74 L-methionine 2.13 9.27 L-phenylalanine 2.2 9.31 L-proline 1.95 10.64 L-threonine 2.09 9.1 L-Tryptophan 2.46 9.41 L-tyrosine 2.2 9.11 10.1 L-valine 2.29 9.74 L-aspartic acid 1.99 3.9 9.9 L-glutamic acid 2.13 4.31 9.67 L-arginine 1.82 8.99 12.5 L-histidine 1.8 6.04 9.33 L-lysine 2.16 9.06 10.54

In certain embodiments, the organic acid in the buffer solution may be present in the composition as a corrosion inhibitor and / or chelating agent.

Preferred bases for use in the buffers of the compositions include amines and quaternary alkylammonium hydroxides. Further examples of counterbases include hydroxylamine, organic amines such as primary, secondary or tertiary aliphatic amines, aliphatic cyclic amines, aromatic amines and heterocyclic amines, aqueous ammonia solutions, and lower alkyl quaternary ammonium hydroxides. . Specific examples of hydroxylamine include hydroxylamine (NH ₂ OH), N-methylhydroxylamine, N, N-dimethylhydroxylamine and N, N-diethylhydroxylamine. Specific examples of primary aliphatic amines include monoethanolamine, ethylenediamine and 2- (2-aminoethylamino) ethanol. Specific examples of secondary aliphatic amines include diethanolamine, N-methylaminoethanol, dipropylamine and 2-ethylaminoethanol. Specific examples of tertiary aliphatic amines include dimethylaminoethanol and ethyldiethanolamine. Specific examples of aliphatic cyclic amines include cyclohexylamine and dicyclohexylamine. Specific examples of aliphatic amines include benzylamine, dibenzylamine and N-methylbenzylamine. Specific examples of heterocyclic amines include pyrrole, pyrrolidine, pyrrolidone, pyridine, morpholine, pyrazine, piperidine, N-hydroxyethylpiperidine, oxazole and thiazole. Exemplary quaternary ammonium hydroxides can be compounds having the formula [NR ₁ R ₂ R ₃ R ₄ ] ⁺ OH ^- wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently an alkyl group, hydroxy Alkyl groups, and combinations thereof. As used herein, the term "alkyl" refers to a straight or branched chain unsubstituted hydrocarbon group of 1 to 20 carbon atoms, or 1 to 8 carbon atoms or 1 to 4 carbon atoms. Examples of suitable alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, and tert-butyl. The expression "lower alkyl" refers to an alkyl group of 1 to 4 carbon atoms. As used herein, the term "hydroxyalkyl" refers to a straight or branched chain unsubstituted hydroxyl group containing hydrocarbon group of 1 to 20 carbon atoms, or 1 to 8 carbon atoms or 1 to 4 carbon atoms. Examples of suitable hydroxylalkyl groups include hydroxylethyl and hydroxypropyl. Suitable quaternary ammonium hydroxide compounds include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrabutylammonium hydroxide (TBAH), tetrapropylammonium hydroxide, trimethylethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide (2-hydroxyethyl) triethylammonium hydroxide, (2-hydroxyethyl) tripropylammonium hydroxide, (1-hydroxypropyl) trimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide and benzyltrimethylammonium hydroxide It includes. Among these bases, aqueous ammonia, monoethanolamine, N-methylaminoethanol, TMAH and TBAH are preferred from the viewpoint of availability and safety. Bases may be used alone or in combination with others.

Buffers are provided such that the pH is in the range of about 5 to about 12, or about 6 to about 11.

Fluoride is present in the compositions described herein. Fluoride containing compounds include compounds of the general formula R ₁ R ₂ R ₃ R ₄ NF, wherein R ₁ , R ₂ , R ₃ and R ₄ are independently hydrogen, alcohol groups, alkoxy groups, alkyl groups, or It is a combination. Examples of such compounds include ammonium fluoride, tetramethylammonium fluoride (TMAF), tetraethylammonium fluoride, tetrabutylammonium fluoride, choline fluoride, and combinations thereof. Further examples of fluorides include boric fluoride, hydrofluoric acid, and choline fluoride. The fluoride is preferably present in an amount of 0.01% to 10% or 0.1% to 5% or 0.2% to 2.5% by weight. In certain embodiments, the fluoride is added to the composition in the form of a fluoride salt such as, for example, TMAF. In this embodiment, TMAF may be commercially available as a 20% aqueous solution. In certain embodiments, the fluoride is added to the composition in the form of a fluoride salt such as, for example, ammonium fluoride. In this embodiment, ammonium fluoride may be commercially available as a 40% aqueous solution.

As mentioned above, water is also present in the compositions disclosed herein. It may be present by chance as a component of another element such as, for example, an aqueous ammonium fluoride solution or a buffered aqueous solution, or may be added separately. Non-limiting examples of water include deionized water, ultrapure water, distilled water, double distilled water, or deionized water of low metal content. Preferably, the water is present in an amount of at least about 50%, or at least about 65%, or at least about 82.5% by weight. In certain embodiments, the water comprises 65-99.7% by weight of the composition, or 82.5-98.8% by weight of the composition.

The compositions disclosed herein may optionally contain up to about 15 weight percent, or about 0.2 to about 10 weight percent corrosion inhibitor. Any corrosion inhibitor known in the art for similar applications may be used, for example those disclosed in US Pat. No. 5,417,877, which is incorporated herein by reference. Suitable corrosion inhibitors can be for example organic acids, organic acid salts, phenols, triazoles, hydroxylamines or acid salts thereof. Examples of specific corrosion inhibitors are citric acid, anthranilic acid, gallic acid, benzoic acid, isophthalic acid, maleic acid, fumaric acid, D, L-malic acid, malonic acid, phthalic acid, maleic anhydride, phthalic anhydride, benzotriazole (BZT), resorci Nols, carboxybenzotriazoles, diethylhydroxylamine and its lactic and citric acid salts, and the like. Further examples of corrosion inhibitors that can be used include catechol, pyrogallol, and esters of gallic acid. Particular hydroxylamines available include diethylhydroxylamine and its lactic and citric acid salts. Other examples of suitable corrosion inhibitors include fructose, ammonium thiosulfate, glycine, lactic acid, tetramethylguanidine, iminodiacetic acid, and dimethylacetoacetamide. In certain embodiments, the corrosion inhibitor may comprise a weak acid having a pH in the range of about 4 to about 7. Examples of weak acids include trihydroxybenzenes, dihydroxybenzenes, and / or salicylic hydroxamic acid. In embodiments where the corrosion inhibitor is an organic acid, the organic acid may be the same as used in a buffer solution. In certain embodiments, the corrosion inhibitor is a mercapto group containing compound, such as but not limited to 2-mercapto-5-methylbenzimidazole and 2-mercaptothiazoline. Another example of a corrosion inhibitor includes a mercapto group containing compound having hydroxyl and / or carboxyl groups on either side of the α or β position of the compound. Specific examples of such mercapto group-containing compounds include 3-mercapto-1,2-propanediol (also referred to as thioglycerol), 3- (2-aminophenylthio) -2-hydroxymercaptan, 3- (2-hydroxyethylthio) -2-hydroxypropylmercaptan, 2-mercaptopropionic acid, 3-mercaptopropionic acid, and combinations thereof.

The composition may also include one or more of the following additives: surfactants, chelating agents, chemical modifiers, dyes, biocides, and other additives. The additive (s) may be added to such an extent that does not adversely affect the pH range of the composition. Some examples of representative additives include acetylene alcohols and derivatives thereof, acetylene diols (nonionic alkoxylated and / or self-emulsifiable acetylene diol surfactants) and derivatives thereof, alcohols, quaternary amines and diamines, Amides (including aprotic solvents such as dimethyl formamide and dimethyl acetamide), alkyl alkanolamines (such as diethanolethylamine), and chelating agents (such as beta-diketones, beta-ketoimines, carboxylic acids, Malic and tartaric acid based esters and diesters and derivatives thereof), and tertiary amines, diamines and triamines. In certain embodiments, carboxylic acids that may be added to the composition into the buffer solution may also act as chelating agents in the composition.

Materials removed with the compositions described herein include ashed photoresists and process residues known in the art, such as sidewall polymers, bales, fences, etch residues, ash residues, and the like. In certain preferred embodiments, the photoresist is exposed, developed, etched, and ashed and then in contact with the compositions described herein. The compositions disclosed herein are compatible with low-k thin films such as HSQ (FOx), MSQ, SiLK, and the like. This composition can be used to prepare ashed photoresists, including positive and negative photoresists, and organic residues, organometallic residues, inorganic residues, plasma etch residues such as metallic oxides, or photoresist complexes at low temperatures such as tungsten, copper It is also effective for stripping titanium-containing substrates with very little corrosion. Moreover, the composition is compatible with a variety of high dielectric constant materials.

During the manufacturing process, a photoresist layer is coated onto the substrate. Using a photolithography process, a pattern is defined on the photoresist layer. The patterned photoresist layer is plasma etched to transfer the pattern to the substrate. Etch residues are produced in the etching step. Next, a residue is formed by ashing the patterned substrate. When ashing the substrate, the main residue to be cleaned is an etchant residue.

The method described herein can be carried out by contacting a substrate having an organic or metal-organic polymer, inorganic salt, oxide, hydroxide, or a complex or combination thereof, present as a thin film or residue, with the described composition. Actual conditions, such as temperature, time, etc., depend on the thickness and the nature of the material to be removed. Generally, the substrate is contacted with, or immersed the substrate in, the vessel containing the composition at a temperature in the range of 20 ° C to 80 ° C, or 20 ° C to 60 ° C, or 20 ° C to 40 ° C. Typical times for exposing the substrate to the composition can range from, for example, 0.1 to 60 minutes, or 1 to 30 minutes, or 1 to 15 minutes. After contact with the composition, the substrate can be rinsed and dried. Drying typically takes place under inert atmosphere. In certain embodiments, rinse containing deionized water with deionized water rinse or other additives may be used prior to, during, and / or after contacting the substrate with the composition disclosed herein.

While the invention will be illustrated in more detail with reference to the following examples, it should be understood that the invention is not to be considered limited thereto.

The exemplary compositions used in the examples were prepared by combining deionized water, fluorides, organic acids and bases, and mixing the components in a vessel at room temperature until all solids dissolved. The obtained composition is shown in Table 3 below.

Exemplary Compositions Composition number Water (wt%) Fluoride (wt%) Organic acid (% by weight) Base (% by weight) Corrosion inhibitor (% by weight) One 96.775 TMAF (0.4) MES (2.2) TMAH (0.625) 2 97.375 TMAF (0.4) HEPES (1.6) TMAH (0.625) 3 96.475 TMAF (0.4) DIPSO (2.5) TMAH (0.625) 4 91.9 TMAF (0.4) EPPS (6.45) TMAH (1.25) 5 96.825 TMAF (0.4) CHES (2.15) TMAH (0.625) 6 95.32 TMAF (0.4) CAPS (3.03) TMAH (1.25) 7 96.29 TMAF (0.4) Glycine (2.06) TMAH (1.25) 8 95.85 TMAF (0.4) Glycine (1.5) TMAH (1.25) Thioglycerol (1.0) 9 96.52 TMAF (0.4) β-alanine (1.83) TMAH (1.25) 10 95.65 TMAF (0.4) β-alanine (1.7) TMAH (1.25) Thioglycerol (1.0)

The pH and etch rate of all the compositions were tested. pH was measured using a 5% aqueous solution at ambient temperature. The results are shown in Table 4 below.

pH and Etch Rate Data Composition number pH Etch Speed (Å / min) Cu TEOS JSR LEB-043 25 ℃ 40 ℃ 25 ℃ 40 ℃ 25 ℃ 40 ℃ One 6.44 <1 <1 nt <1 nt nt 2 7.83 One One nt <1 nt nt 3 7.93 2 3 nt <1 nt nt 4 7.88 2 3 nt <1 nt nt 5 9.68 <1 One nt <1 nt nt 6 10.76 One nt <1 nt <1 <1 7 9.35 50 nt <1 nt nt nt 8 9.73 One One nt <1 nt nt 9 10.13 83 nt <1 nt nt nt 10 10.01 One One nt <1 nt nt

nt: not tested.

Etch rates were obtained for blanket silicon wafers containing copper, doped non-tetracontained tetraethylorthosilicate (TEOS) and JSR LEB-043 (porous methylsilsequioxane (MSQ) thin film from JSR, Inc.). Measurements were performed at exposures of 5, 10, 20, 40 and 60 minutes at temperature intervals of 25 ° C and 40 ° C. Thickness measurements were performed at each time interval and graphed using the “Minimum Square Fit” model for the results of each exemplary composition. The calculated slope of the “least square fit” model of each composition is the resulting etch rate, expressed in Angstroms / minute (Å / min). In copper etch rate or oxide etch rate measurements, the wafer was provided with a blanket layer that knew the thickness deposited thereon.

For Cu etch rate, the initial thickness of the wafer was measured using a CDE ResMap 273 Four Point Probe. After the initial thickness was measured, the test wafer was immersed in the exemplary composition. After 5 minutes, the test wafer was removed from the test solution, rinsed with deionized water for 3 minutes, and dried completely under nitrogen. The thickness of each wafer was measured and if necessary the procedure was repeated for the test wafer.

For TEOS and JSR LEB-043 etch rates, the initial thickness was measured using a FilmTek 2000 SE Spectroscopic Ellipsometer / Reflectomer. Approximately 200 ml of test solution was placed in a 250 ml beaker, stirred and, if necessary, heated to reach a specific temperature. When only one wafer was placed in the beaker containing the solution, the dummy wafer was placed in the beaker. After 5 minutes, each test wafer was washed with deionized water for 3 minutes and dried under nitrogen. Next, the substrate was baked at a temperature of 110 ° C. for approximately 10 minutes. Each wafer was measured and the procedure repeated if necessary.

The effectiveness of the exemplary composition to remove residue from the silicon wafer test substrate was tested. The wafer had a low-k, JSR LKD-5109 porous MSQ thin film (provided by JSR, Inc.), a titanium nitride barrier layer, a copper metallization layer, a BARC layer, a photoresist pattern, which patterned plasma etching and ashing processes. Were etched and ashed. Next, the substrate was treated by immersing it in the exemplary composition. In this step, one or more test wafers were placed in a 600 ml beaker containing 400 ml of each exemplary composition. The 600 ml beaker further included a 1 inch stir bar rotating at 400 rpm. Next, the exemplary composition containing the wafer (s) therein was heated at a certain temperature for a certain time. After exposure to the exemplary composition, the wafer (s) were rinsed with deionized water and dried with nitrogen gas.

Wafers were excised to make edges and examined using scanning electron microscopy (SEM) for various predetermined sites on the wafer.

Residual removal efficacy and preservation of the substrate were graded by visual inspection of SEM micrographs at 100,000-fold magnification. The results are shown in Table 5 below.

Residue removal data Composition number Time (min) Temperature (℃) Residue removal Board Damage One 15 40 - - 2 15 40 + - 3 15 40 ++ - 4 15 40 - - 5 15 40 ++ - 6 15 40 ++ - 7 15 40 nt nt 8 15 40 ++ - 9 15 40 nt nt 10 15 40 ++ -

nt: not tested.

sign Residue removal Board Damage

++ practically unacceptable

+ ~ 10% to ~ 90% not substantial

Substantially none substantially (ie 100,000 times)

Invisible damage at magnification, or

Of acceptable levels at this scale

Visible damage)

Since the cleaning composition of the present invention is substantially free of added organic solvent and has a specific range of pH, there is an effect of removing residual photoresist and process residue with high selectivity.

Claims (25)

A composition for removing residue from a substrate, (a) water; (b) one or more fluorides; And (c) (i) at least one organic acid selected from the group consisting of aminoalkylsulfonic acids and aminoalkylcarboxylic acids; And (ii) a pH buffer system comprising at least one base selected from the group consisting of amines and quaternary alkylammonium hydroxides, A composition substantially free of added organic solvent and having a pH in the range of about 5 to about 12. The composition of claim 1 further comprising one or more corrosion inhibitors suitable for inhibiting corrosion of the substrate. The method of claim 2, wherein the one or more corrosion inhibitors are citric acid, anthranilic acid, gallic acid, benzoic acid, malonic acid, maleic acid, fumaric acid, D, L-malic acid, isophthalic acid, phthalic acid, lactic acid, maleic anhydride, phthalic anhydride, catechol , Pyrogallol, ester of gallic acid, benzotriazole, carboxybenzotriazole, fructose, ammonium thiosulfate, glycine, tetramethylguanidine, iminodiisacetic acid, dimethylacetoacetamide, thioglycerol, trihydroxybenzene, At least one component selected from the group consisting of dihydroxybenzene, salicylic hydroxamic acid, and mixtures thereof. The composition of claim 1, wherein the at least one corrosion inhibitor is thioglycerol. The composition of claim 1 further comprising at least one surfactant. The composition of claim 5, wherein the at least one surfactant is at least one component selected from the group consisting of acetylene alcohols, derivatives thereof, acetylene diols and derivatives thereof. The compound of claim 1, wherein the at least one fluoride has a composition of the general formula R ₁ R ₂ R ₃ R ₄ NF, wherein R ₁ , R ₂ , R ₃ and R ₄ are independently hydrogen, alcohol group, alkoxy group, alkyl group And combinations thereof. 8. The composition of claim 7, wherein the at least one fluoride is a component selected from ammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrabutylammonium fluoride, choline fluoride, and combinations thereof. The composition of claim 1, wherein the at least one fluoride is tetramethylammonium fluoride. The composition of claim 1, wherein the at least one organic acid is at least one component selected from the group consisting of MES, HEPES, DIPSO, EPPS, CHES, and CAPS. The composition of claim 1, wherein the at least one organic acid is at least one component selected from the group consisting of glycine and β-alanine. The compound of claim 1 wherein the quaternary ammonium hydroxide compound comprises a compound having the general formula [NR ₁ R ₂ R ₃ R ₄ ] ⁺ OH ⁻ , wherein R ₁ , R ₂ , R ₃ and R ₄ are each independently And an alkyl group, a hydroxyalkyl group, and a combination thereof. The method of claim 12, wherein the quaternary ammonium hydroxide compound is selected from the group consisting of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, (2-hydroxyethyl) trimethylammonium hydroxide, 2-hydroxyethyl) triethylammonium, (2-hydroxyethyl) tripropylammonium, (1-hydroxypropyl) trimethylammonium hydroxide, and combinations thereof. The composition of claim 1, wherein the at least one base is tetramethylammonium hydroxide. The composition of claim 1, wherein at least one fluoride is tetramethylammonium fluoride and at least one base is tetramethylammonium hydroxide. The method of claim 1, wherein the at least one fluoride is tetramethylammonium fluoride and at least one base is tetramethylammonium hydroxide, and the at least one organic acid comprises at least one component selected from the group consisting of MES, HEPES, DIPSO, EPPS, CHES and CAPS. A composition comprising. The composition of claim 1, wherein the at least one fluoride is tetramethylammonium fluoride and at least one base is tetramethylammonium hydroxide, and the at least one organic acid comprises at least one component selected from the group consisting of glycine and β-alanine. The composition of claim 1 wherein water comprises 65-99.7% by weight of the composition, at least one organic acid comprises 0.1-20% by weight of the composition, at least one base comprises 0.1-10% by weight of the composition, and fluoride Composition comprising 0.1-5% by weight of the silver composition. The composition of claim 18, wherein the normal ratio of one or more organic acids to one or more bases is from 10: 1 to 1:10. The composition of claim 1, wherein the composition is formulated to substantially avoid substrate damage. A method for removing a residue from a substrate comprising contacting the residue with a composition at a temperature and time effective to remove the residue from the substrate, The composition is (a) water; (b) one or more fluorides; And (c) (i) at least one organic acid selected from the group consisting of aminoalkylsulfonic acids and aminoalkylcarboxylic acids; And (ii) a pH buffer system comprising at least one base selected from the group consisting of amines and quaternary alkylammonium hydroxides, And substantially no organic solvent added and having a pH in the range of about 5 to about 12. The method of claim 21, wherein the temperature is 20 ° C. to 80 ° C. and the time is 1 to 30 minutes. The method of claim 21, wherein all residues on the substrate are removed without substantially damaging the substrate. Coating the photoresist on at least a portion of the substrate; Lithographically defining a pattern on the photoresist; Transferring the pattern onto at least a portion of the substrate; Etching the pattern onto a substrate to form a patterned substrate; Ashing the photoresist to heat the patterned substrate to a temperature sufficient to provide a residue; And (a) water; (b) one or more fluorides; And (c) (i) at least one organic acid selected from the group consisting of aminoalkylsulfonic acids and aminoalkylcarboxylic acids; And (ii) a pH buffer system comprising at least one base selected from the group consisting of amines and quaternary alkylammonium hydroxides, Removing the residue by contacting the residue with a composition substantially free of added organic solvent and having a pH in the range of about 5 to about 12. The method of claim 24, wherein the residue on the patterned substrate is removed without substantially damaging the patterned substrate.